This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The aim is to generate a protein interaction map for M.tuberculosis in the persistent state. There is great potential that this information will accelerate the identification and prioritization of drug targets for antibiotics that kill persistent M.tuberculosis. Proteins will be tagged in M.tuberculosis strains grown in the lab of Prof. Jeffrey Cox, purified using affinity chromatography, and identified by MALDI-TOF and LC/MS/MS mass spectrometry. Initially, approximately 20 proteins will be purified from log phase cultures, and ultimately the project aims to purify approximately 200 proteins from persistent M.tuberculosis cultures, with mass spectrometry analysis carried out on the successful purifications, to generate a physical interaction map for the persistence regulon.